Embodiments of the inventive concept relate to a semiconductor memory device, and more particularly, to a semiconductor memory device including spin-transfer torque magnetic random access memory (STT-MRAM).
Semiconductor memory devices may be classified as volatile and non-volatile according to their operative nature. MRAM is one type of non-volatile semiconductor memory device including a resistive element that may be programmed to a desired data state, corresponding to a selected resistive state, where such data state is stably retained in the absence of applied power. SST-MRAM has been referred to as universal memory because it combines the low cost and high data capacity features associated with a dynamic random access memory (DRAM) with the fast operating speed associated with a static random access memory (SRAM).
Magnetic memory, and more specifically, MRAM has received a lot of attention due to its fast read/write speed, high durability, non-volatile operating nature, and low power consumption during operation. MRAM stores information using a magnetic material as a data storage medium. STT-MRAM is a type of MRAM. A magnetic tunnel junction (MTJ) can be used in typical STT-MRAM.